International Scholarly Research Notices / 2013 / Article / Tab 6 / Research Article
A Comparative Study of Some Regression Models to Estimate the Global Solar Radiation on a Horizontal Surface from Sunshine Duration and Meteorological Parameters for Ghardaïa Site, Algeria Table 6 Comparison between measured and estimated monthly global solar radiation (Wh/m2 ).
Measured Linear
(%)Quadratic
(%)Logarithmic
(%)Exponential
(%)January 3871 3879.75 −0.226 3924.54 −1.383 4054.48 −4.74 3812.38 1.514 February 4842 4768.92 1.509 4746.43 1.974 5229.17 −7.996 4693.99 3.057 March 5926 5836.64 1.508 5863.69 1.051 6176.79 −4.232 5735.38 3.217 April 7339 7346.01 −0.096 7393.31 −0.74 7779.2 −5.998 7261.09 1.062 May 7745 7745.06 −0.001 7809.96 −0.839 8203.51 −5.92 7617.16 1.651 June 7812 7826.41 −0.184 7930.14 −1.512 8239.29 −5.47 7699.28 1.443 July 7503 7492.63 0.138 7484.43 0.248 7985.6 −6.432 7437.93 0.867 August 7090 7224.91 −1.903 7377.84 −4.06 7576.91 −6.868 7191.04 −1.425 September 6036 6024.21 0.195 6054.37 −0.304 6371.7 −5.562 5898.47 2.278 October 4824 4821.02 0.062 4869.69 −0.947 5128.76 −6.318 4737.96 1.784 November 4030 4026.13 0.096 3978.2 1.285 4224.29 −4.821 3963.04 1.662 December 3437 3427.06 0.289 3626.54 −5.515 3728.76 −8.489 3349.42 2.548